Establishing K-levels and prescribing transtibial prostheses using six-minute walk test and one-leg standing test on prosthesis: a retrospective audit

Abstract

Rehabilitation programs after amputation often include fitting a prosthesis, but prescriptions vary under similar circumstances. The US Medicare Functional Classification Level (K-level) is a scale for describing functional abilities of persons after lower-limb amputation (from 0 = no ability or potential to ambulate, to 4 = prosthetic demands of a child/active adult/athlete). Different outcome measures are used to assess K-level, including six-minute walk test (6MWT). We attempted to predict the assigned K-level of unilateral transtibial prosthesis users from their results of 6MWT and one-leg standing test on prosthesis (OLSTP). Outpatients who had been rehabilitated and fitted with transtibial prosthesis at the University Rehabilitation Institute in Ljubljana in 2014 were included in a retrospective audit. The data were analysed using receiver-operating-characteristics curves, linear discriminant analysis, classification trees and ordinal logistic regression. Among the 120 patients (aged 39–90, mean 67 years; 79% men), eight belonged to K1 level, 94 to K2, and 18 to K3 or K4; 61 could not stand on the prosthesis, eight stood on it for 1 s, and 51 stood on it for 2 s or more. With a simple classification rule based only on 6MWT (130 m threshold for K2/K3/K4 vs. K1, 340 m for K3/K4 vs. K1/K2), we observed sensitivity and specificity close to 90%. The more sophisticated statistical approaches yielded substantially similar and comparably accurate results. 6MWT and OLST could therefore be used as predictors for transtibial prosthesis prescription in clinical practice.

Quantitative methods used to evaluate balance, postural control, and the fear of falling in lower limb prosthesis users: A systematic review

“…The results from the current study showed a large bias toward recruiting males in research in this area. The reported 26.4% of female lower limb prosthesis users participating in studies was lower than what has been reported in a highly regarded national amputation registry (SwedeAmp; 39%), 234 as well as in previous research (34.5%–38.4%) such as Claessen et al 235 and Ziegler-Graham et al 236 The present authors think it is noteworthy that, of the (n = 161) articles reporting characteristics on sex in the balance articles in Supplemental Table (Supplemental Digital Content 2, http://links.lww.com/POI/A170) 12-14,19-23,25,26,28,29,31-42,44,45,47,48,50-56,58,59,62-69,71-75,77-85,88-90,92,94-102,105-120,122-136,138,140-153,155,157-165,167-179,181-184,186-198,230,231 and the (n = 62) articles of balance confidence, 4,6,8,14,44,71,78,81,83,94,134,138,143,145,147,148,150,151,153,155,157,159,163,165,172,175-178,183,193,196,199-203,205-209,211-229 29.2% and 19.4% respectively, included male sex exclusively. There were only (n = 2) studies with female participants, one balance article 231 and one balance confidence article.…”

“…Studies that explicitly stated limitations or confounders were just over two-thirds of the total (Table 2),. 13,14,19–22,24,28–56,71,74,76,77,80–95,108,109,115–132,140–145,147–165,169–180,182–184,188–191,193–198 The most commonly mentioned limitation was small sample size, 20,22,24,28,29,32,33,35,37,39,40,42,45,47,52,54-57,74,80,82,86,87,89,93,95,109,118,119,121,123,126,129,141,143,145,148,149,154-159,161,164,169,172,183,198 followed by generalizability issues, 14,19-21,34,38,41,42,44,52-56,80,81,87,89,109,127-130,142,148,151,155,156,162,171,175-177,184,188,189,191,193,196 recall bias, 14,148,150,157,171,173,182,184 heterogeneous groups, 29,42,54,89,142,174,176,177 homogenous groups, 21,38,39,44,45,91,164 and convenience samples. 14,161,176,177,196…”

“…One leg stance test appeared with various names in about some studies. 109,145,162,174,[181][182][183][184][185][186][187] The protocol of Sensory Organization Test was also used. 12,22,25,26,43,47,52,53,57,58,78,105 Four Square Step Test, or a modified version of it, was less common 74,117,134,148,151,158,169,173,188 and tests involving Narrowing Beam Walking or Narrow Ridge Balance were also used (Figure 2).…”

A new valid Walking Aid Scale better predicts distance walked by prosthesis users than Prosthetic Mobility Questionnaire 2.0 and Activities-Specific Balance Confidence Scale

“…THE 6-MINUTE WALK TEST (6MWT) is a generic timed test used to assess aerobic capacity and endurance, and to monitor prosthetic walking performance [9]. It measures the distance an individual is able to cover over 6 min on a hard, flat surface.…”

“…Also, the Prosthetic Mobility Questionnaire (PMQ) in its original [4] and revised version (PMQ 2.0) represents a recent Rasch-validated refinement of the PEQ-MS, with even better psychometric characteristics [5]. Other tools are the Activities-specific Balance Confidence Scale (ABC-5), a self-report measure of confidence in performing various activities without falling [6,7], and the 6-Minute Walk Test (6MWT), a performance-based measure of mobility (distance walked in a fixed time) [1,8,9].…”